JP7421485B2 - System and method for determining container health by optical measurement - Google Patents

Description

The present disclosure relates to determining the health of a closed container by making optical measurements across the outer surface of the container for the detection of gas leaks from the interior of the container. The measurements include applying a mechanical force to the container and taking optical measurements across the outer surface of the container to detect gas leakage from the interior of the container. In particular, the present disclosure relates to non-destructive leak testing of containers such as packages, bags, trays, etc.

Verifying the integrity of sealed containers is important in many industrial environments. Some examples include quality control of packaging for products such as food and pharmaceuticals. The integrity of a sealed container may be compromised by defects in the sealing process or barrier material, or due to damage during production or shipping. Healthiness includes, for example, keeping the contents of the package inside the container, keeping any prefilled gas inside the container at a desired level, and preventing external atmospheric gases from entering the container. It is important for several reasons, including: The latter two points can be very important in order to prevent the contents of the container from deteriorating. For example, oxygen or water vapor (humidity) levels often determine the shelf life of a product. Other motivations for detecting leaks in containers include, for example, verifying the integrity of the container against other substances such as liquids, including but not limited to water, bacteria, viruses, and other biological agents. It's about doing. Gas-based leak detection can be used to measure leak size or ensure package integrity with respect to these other substances.

Several means are known in the art for verifying the integrity of a container. For example, a flexible container may be subjected to mechanical forces to check the resistance of internal gas pressure. However, this method is typically not suitable for detecting small leaks and also carries the risk of damaging the container. Some types of containers can be inspected by automated vision systems to detect abnormalities, but this too may not detect small leaks and this method limited to containers. Small leaks can be detected by penetration tests using pigments or tracer gases such as helium, but such tests are often destructive. Another method is to remove the container in an external atmosphere, for example by placing the container in a vacuum chamber or by overpressuring the container with atmospheric air or other gases, or by combining these techniques. may be exposed to external fluctuations. This method describes how to detect a leak in a container by controlling or measuring one or more parameters that may vary, for example, as a series of external gases or variations in gas components, when a leak is present. Additional measures are required. As another example, if the container contains a gas species that is not present in significant concentrations in normal air, a gas detector may be installed in the test chamber (or at its outlet) to detect the presence of the gas species. placed and indicating a leak.

Non-destructive optical detection of gases inside a package for quality control is disclosed in European Patent Application No. 10720151.9 (Svanberg et al.). The principles of optical detection of gas in the head space of a package for the purpose of indicating leaks are known in the art. This method is based on the fact that the gas inside the package can deviate from the expected gas composition due to reaction with the surrounding atmosphere through leakage. However, in normal atmosphere, for small leaks it can take a very long time before there is a detectable shift in gaseous components inside the package, making this method impractical in many situations. There is.

A faster determination of container health based on optical measurements of gas composition/pressure inside a sealed container is addressed by WO 2016/156622. Here, the container is exposed to an environment with forced changes in the concentration/pressure of the gas, which causes the natural changes observed in European Patent Application No. 10720151.9 if a leak is present. causes faster changes inside the container compared to

Another method is to use a gas detection cell where the leaking gas is extracted and detected. Disadvantages of this method include, for example, the time for detection, the complexity of the system, the high cost, the dilution of the gas, and the large amount of leaked gas required to be able to detect the leak. be.

None of the methods in the art mentioned above are suitable for detecting leaks. One example is for in-line measurements; therefore, new and improved devices and methods for detecting leaks in such containers would be advantageous.

Accordingly, embodiments of the present disclosure preferably provide a method for non-destructively determining the health of a closed container by light transmitted above the outer surface of at least one side of the container, as claimed in the appended claims. The aim of the invention is to reduce, alleviate, or eliminate one or more deficiencies, disadvantages, or problems in the art as described above by any one or in any combination of systems or methods within the scope of the present invention. This is the purpose.

In one aspect of the present disclosure, a method of determining the health of a closed container containing at least one gas is described. The method includes applying a mechanical force to at least one side of the container and using an optical sensor to transmit an optical signal across at least a portion of an outer surface of at least one side of the container. But that's fine. The optical sensor may be sensitive to at least one gas inside the container.

The method further includes detecting the transmitted optical signal and determining, based on the detected transmitted optical signal, whether the level of the at least one gas inside the container has changed outside the container. including doing.

In some examples of the methods, the optical sensor may be a light source and a detector. Light is transmitted between a light source and a detector, and the detected optical signal may be an absorption signal, such as a Tunable diode laser absorption spectroscopy signal.

Some examples of such methods include the force being applied using a deformable member such as a roller or a glider.

In some examples of such methods, the container may be a MAP food package, such as a bag or tray.

Some examples of such methods may include determining the health of the containers in series, such as on a conveyor belt.

Some examples of such methods include filling the perimeter of the container with a neutral gas, such as nitrogen ( _N2 ), during or during the transmission of the optical signal.

In some examples of the disclosed methods, the gas measured may be carbon dioxide ( _CO2 ).

Some examples of such methods may include introducing a gas to create a flow around the package to transport the leaking gas to the optical signal.

In a further aspect of the present disclosure, a system for determining the health of a sealed container containing at least one gas is disclosed. The system includes a member or device for applying a mechanical force to at least one side of the container, at least one gas-sensitive optical sensor. The sensor may be configured to transmit an optical signal across at least a portion of the outer surface of at least one side of the container.

The system further comprises a control unit for determining whether the level of the at least one gas inside the container has changed outside the container based on the detected transmitted optical signal.

In some examples of the disclosed systems, the member may be a deformable member such as a roller or a glider.

In some examples of the disclosed systems, an extractor or suction member, such as a hole connected to a pump or fan, is proximate the sensor to increase the concentration of at least one gas adjacent the optical sensor. It may be arranged as follows.

In some examples of the disclosed systems, a roof may be placed above the optical sensor to increase the concentration of the at least one gas adjacent the optical sensor.

Some examples of the disclosed systems may include two or more sensors located on different sides of the container.

In some examples of the disclosed systems, the light may be bent using optical systems such as mirrors to pass over the surface of the container multiple times.

In some examples of the disclosed systems, light may be bent using optical systems such as mirrors to pass over two or more surfaces of the container.

In some examples of the disclosed systems, the gas measured may be carbon dioxide ( _CO2 ).

Some examples of the disclosed systems may include a device configured to introduce gas to create a flow around the package to transport leaking gas to the optical signal.

Some advantages of the disclosed system and method over known systems and methods include that the disclosed system requires fewer parts and/or steps in the detection process; It cannot be more complicated than the method. The response for detecting leaks can be improved, the signal from the detected gas can be increased, and the sensitivity of leak detection can be improved.

The described sensor arrangement may also be used to detect where leaks are located in the package.

The disclosed methods and systems may also be influenced by ambient gas and environment.

The term "comprising" when used in the specification is deemed to indicate the presence of the described feature, integer or element, but one or more other features, integers or elements. , or the existence or addition of these groups is not excluded.

Figure 3 illustrates an example arrangement of rollers to apply a force to at least one side of a container. FIG. 7 illustrates an exemplary placement of a roof proximate a light sensor to increase the concentration of leaked gas. FIG. 7 illustrates an exemplary placement of a roof proximate a light sensor to increase the concentration of leaked gas. 3 illustrates an exemplary arrangement of optical sensors used in applying mechanical force in the system. 5 illustrates an exemplary arrangement of optical sensors used in applying mechanical forces in the system. 3 illustrates an exemplary arrangement of optical sensors used in applying mechanical force in the system. 3 illustrates an exemplary arrangement of optical sensors used in applying mechanical force in the system. 3 illustrates an exemplary arrangement of optical sensors used in applying mechanical force in the system. 3 illustrates an exemplary arrangement of optical sensors used in applying mechanical force in the system. 3 shows an exemplary arrangement of gas flow applied from below the package. Figure 3 shows a schematic diagram of the measurements. This shows how to measure gas leaking from a closed container. 3 illustrates measurements made using the techniques described herein.

Examples of the present disclosure will now be described with reference to the accompanying drawings. However, this disclosure may be embodied in many different forms and should not be construed as limited to the examples set forth herein. Rather, these examples are provided so that this disclosure will be thorough, complete, and fully convey the scope of the disclosure to those skilled in the art.

The following disclosure is an example of this disclosure that is applicable to determining the health of a container by making optical measurements across the outer surface of the container for the detection of gas leaks from the interior of the container. is focused on. The measurements may include applying a mechanical force to the container and taking optical measurements across the outer surface of the container for detection of gas leaks from the interior of the container. The present disclosure relates to non-destructive leak testing of closed containers such as packages, bags, trays, etc. For example, the disclosed systems and methods can be used to improve the detection of leaks from closed packages or containers. However, it will be understood by those skilled in the art that this description is not limited to this application, but can be applied to many other systems needed to determine the health of closed containers.

The container may be a closed bag or tray containing at least one gas. Some examples may be a container with a modified atmosphere (MAP). Modified atmospheres are commonly used in packaging, for example, to improve the shelf life of food packaging, pharmaceuticals, and the like. Commonly used gases are carbon dioxide (CO ₂ ) or nitrogen (N ₂ ) to reduce the amount of oxygen (O ₂ ). This is done to slow down the growth of aerobic organisms and prevent oxidative reactions. Therefore, it is important to monitor these packages and check for leaks, eg, during packaging. Apart from carbon dioxide (CO ₂ ) and oxygen (O ₂ ), depending on the container and the product, other gases can be monitored as well.

FIG. 1 shows a schematic example of an embodiment 60 of the optical sensor according to FIGS. 3A-3F. In the figure, a light source 210 transmits an optical signal 212 to a detector 211 across an outer surface 201, such as the top surface of a container 200.

In these examples, a mechanical member or device 220, such as a deformer, is used to apply a force to at least one side of the container 200. The applied force may deform the container 200 to some extent. Due to the deformation of the container 200, the gas 231 inside the container 200 may leak out through holes or cracks 230 that may be present. When using mechanical member 220, the amount of gas 231 that may escape from any hole or crack 230 may be greater than the amount that would naturally escape. This prevents leakage from the container due to holes, cracks, bad joints or glued seals or seams, tears in the package, due to the introduction of foreign objects that may be the contents of the package or part of the contents of the package. Improve your chances of detecting a leak or receiving an indication.

In the drawings, rollers 220 are used to apply force to the upper side 201 of the container 200. The rollers 220 facilitate the passage of the container 200 below the mechanical member 220 or the movement of the mechanical member 220 above the container 200. Alternatively, the mechanical member 220 may be a glider, such as a beam or a plate, so that it is handled with low frictional forces against the container 200.

Alternatively, in some examples, mechanical member 220 may temporarily press against side 2001 of container 200 during measurements. The pressing may be performed in a vibrating manner while the container 200 is moving along a conveyor belt, for example.

Alternatively, in some examples, a jet of gas, such as air, may be used to apply a force to side 201 of container 200 without mechanical member 220.

Alternatively, rather than pressing against the upper side 201 of the container 200, the force may be applied to any side or sides of the container 200, as shown in FIGS. 1, 2A, and 2B. You can.

A force applied to the side of the container, either by a mechanical member such as a roller, glider, or pusher, or by a jet of gas, temporarily forces the container to vent its internal gas through any holes that may be present. to transform. This increases the concentration of leaked gas outside the vessel, thereby increasing the signal which may improve the sensitivity of the system, thereby making it more likely that leaks from smaller holes would be detected than would otherwise be detected. Improve detection rate.

In the schematic example shown in FIG. 1, the container 200 may be moved relative to the sensor and the mechanical member 220 used to deform the container 200. Container 200 may be moved, for example by a conveyor belt. Alternatively, container 200 is fixed while mechanical member 220 and sensor are moved relative to container 200.

Additionally and/or alternatively, in some examples, an extractor member or suction member (not shown) may be positioned adjacent the laser beam 212 of the sensor. In some examples, an extractor or suction member may be positioned adjacent to both the laser beam 212 and the mechanical member 220 to deform the container 200.

An extractor or suction member may be used to increase the concentration of gas 231 leaking from the container 200 in proximity to the sensor, thereby increasing the signal leading to increased sensitivity of the system. The increased sensitivity allows smaller holes or cracks 230 to be detected, but also makes detection faster.

The extractor member or suction member may be made from a beam or tube with a lumen or hole arranged along the side facing the container 200. The cavity may be connected to a pump, fan, or extractor, which, when used, draws air through the holes. Any gas 231 that escapes from a hole or crack 230 in the container 200 is attracted to the extractor or suction member which increases the concentration of the leaked gas in the beam path of the sensor, thereby increasing the signal.

2A and 2B show two different schematic examples of embodiments 70, 80 to further improve the detection rate and sensitivity of the system. Enhancement is achieved by adding a roof, screen, cap, or dome 321 above the light beam 312 transmitted between the light source 310 and the detector 311. be done. A roof, shield, cover, or dome 312 can increase the concentration of gas 331 leaking from the crack hole 330 adjacent to the beam 312.

Additionally, in some examples, a roof, shield, cover, dome 312 may be used in conjunction with a mechanical member or device 320 that is used to apply a force to one side 301 of the container 300. .

In the example shown in FIG. 2A, a roof, shield, covering, or dome 321 is positioned to cover the entire side 301 of the container 300. A roof, shield, covering, or dome 321 may be provided with the hole 322 to allow the light beam 312 to be transmitted across the outer surface 301 of the container 300.

In the example shown in FIG. 2B, a roof, shield, covering, or dome 321 is positioned locally above the light beam.

The roof, shield, or covering 321 may have any suitable shape besides the curved shape shown in FIGS. 3A and 3B, and the roof, shield, or covering 321 may have, for example: It may be dome shaped or flat.

Embodiments of arrangement as shown in FIGS. 1, 2A and 2B may be performed in a non-serial or serial manner while the packages are traveling along a conveyor belt. Embodiments may, in some examples, be such that the sensor moves relative to the container, rather than the container moving relative to the sensor.

Additionally, in some examples, the periphery of the container may be filled with a neutral gas, such as nitrogen ( _N2 ), during or during the transmission of the optical signal. When filling with neutral gas between measurements, the surroundings can be purified from any gases that could interfere with the measurements. Therefore, sensitivity may be increased.

When applying a neutral gas around the container during the measurement, such as filling with a constant flow rate, the background of the measurement is low. Therefore, leaked gas may be more easily detected, thereby increasing sensitivity.

In the illustrated example, absorption is measured to determine if there is a leak from the container. Alternatives may use optical sensors based on laser induced fluorescence, where the optical signal detected is a disperse spectra or an excitation spectra. Although the configuration is similar, the light source may be a pulsed laser terminated with a beam blocker while the detector moves to detect the fluorescent signal. An alternative configuration may be planar laser-induced fluorescence, where an optical system is used to form the laser beam onto a surface that may cover the entire side of the container.

3A-3F illustrate example configurations of optical sensors used in systems or methods during application of mechanical force.

FIG. 3A shows a schematic exemplary configuration 10 of an optical sensor for determining whether there is a leak from a closed container 100.

The optical sensor includes a light source 110, such as a laser, and a detector 111. The light source may be a white light source or at least one laser light source such as a diode laser, a semiconductor laser, etc. The wavelength or wavelength range used for the light source is selected to match the absorption spectra of the at least one gas inside the container 100. The detector 111 may be, for example, a photodiode, a photomultiplier, a CCD detector, a CMOS detector, or an InGaAs detector selected from those capable of detecting the wavelength or wavelength range of the light source 110.

The light source 110 transmits a light signal 112 that spans at least a portion of the outer surface 101 of the side of the container 100. Optical signal 112 is transmitted above outer surface 101, such as adjacent to outer surface 101 or above outer surface 101 at a distance. The optical signal 112 may be transmitted from side to side across the outer surface 101 , such as across, or at an angle or along the outer surface 101 , such as at a diagonal of the outer surface 101 . good. Optical sensors may transmit optical signals 112 above the container 100, along the sides of the container, or below the container.

FIG. 3B shows the schematic configuration 10 of the optical sensor in FIG. 3A from another angle.

Alternatively, for the configuration shown in FIGS. 3A and 3B, light source 110 and detector 111 may be placed on the same side, and the light is directed from a mirror, etc., placed opposite light source 110 and detector 111. By having the optical signal 112 reflected at a reflective element, it may be transmitted to span the outer surface 101 twice.

FIG. 3C shows a further configuration 20 of the optical sensor. In this example, a light signal 112 is transmitted from a light source 110 to a detector 111 across three outer surfaces 101 , 102 , 103 on three sides of the container 100 . The optical signal 112 is bent by reflective elements 113a, 113b, such as mirrors in this example. By using only one reflective element 113a, 113b, the optical signal 112 may be transmitted across two outer surfaces rather than three as shown. Alternatively, the optical signal 112 may be transmitted across the four outer surfaces of the container 100, as shown in FIG. 3D with a further configuration 30 of the optical sensor by adding a third reflective member 113c. good.

Additionally and/or alternatively, the optical signal 112 may be transmitted across additional exterior surfaces of the container 100 in some examples by different optical elements, such as mirrors, beam splitters, and prisms. This may also include the use of additional detectors.

FIG. 3E shows a further schematic arrangement 40 of a light sensor, in which a light signal 112 is transmitted from a light source 110 to a detector 111. The optical signal 112 is bent using two reflective elements 113a, 113b to have the light beam reflected across the outer surface 110 of the container 100 in the illustrated example. Other configurations are possible where only one reflective element is used to have the optical signal 112 transmitted twice across the outer surface 101.

Alternatively, three or more reflective elements 113a, 113b may be used to have the light transmitted across the outer surface 101 four or more times.

FIG. 3F shows a schematic example of an arrangement 50 in which two sensors are used spanning two outer surfaces of the container 100. The first optical sensor includes a light source 110 that transmits an optical signal 112 across a first outer surface 101 of the container 100. The second optical sensor includes a light source 114 and a detector 111 that transmits an optical signal 116 across the second outer surface 102 of the container 100. Additional optical sensors may be used to span additional outer surfaces of container 100.

In the examples given in Figures 3A-3F, the measurements are based on absorption spectroscopy, such as Tunable diode laser absorption spectroscopy. If a change in the gas signal is detected consistent with at least one gas inside the container, the container is considered leaky given by a certain threshold. Leakage may be due to poor joints or glued seals or sutures, such as foils to the edges of the tray or the opening of the bag. If the species inside the container is present in the ambient background, such as carbon dioxide (CO ₂ ), an increase in the absorption peak of CO ₂ compared to the background will indicate that the container is This may indicate a leak.

FIG. 4 shows a schematic example of an arrangement 90 in which an additional gas flow 501, e.g. is introduced to increase gas transfer to the beam 512 transmitted between the two. In this example, light ray 512 passes above the package. Alternatively, any configuration described with respect to FIGS. 3A-3F may be used. For example, if the leak is on the bottom side of the package 500, it may be beneficial to introduce the gas flow 501 from below to help the leaking gas reach the light beam 512. The introduced gas flow 501 creates a flow, which may be laminar or turbulent, or a mixture thereof, towards and through the light beam 512 and across the surface of the package 512. You may. The introduction of gas takes place in this exemplary illustration through a device 502 comprising a number of small holes across the surface, which act as exhaust ports. The device may be connected to a gas inlet 503. Gas introduction may also be performed in other ways, such as by a single discharge nozzle or porous material. Gas introduction may also occur on other sides of the package.

An advantage of this configuration 90 is that it facilitates transporting leaking gas into the beam 501. This can increase the signal regarding leakage gas.

The arrangement 90 shown in FIG. 4 may be used with members or devices for applying mechanical force to the package 500, as described with respect to FIGS. 1, 2A, and 2B.

The systems disclosed herein further include a control unit for determining whether the level of at least one gas inside the container has changed outside the container based on the detected transmitted optical signal. May include. All determinations or calculations described herein may be performed by a control unit or data processing device (not shown) connected to the detector. The control unit may be a data processing device and may be implemented by special purpose software (or firmware) running on one or more general purpose or special purpose computing devices. As used herein, each "element" or "means" of such computing device refers to the conceptual equivalent of a method step, and between the element/means and a particular part of the hardware or software routine. It should be understood that there is not necessarily a one-to-one correspondence. A piece of hardware comprises different means/elements. For example, a processing unit functions as one element/means when executing one instruction, but as another element/means when executing another instruction. Furthermore, one element/means may in some cases be executed by one instruction, while in some other cases it may be executed by multiple instructions. Such software-controlled computing units include, for example, CPUs (“central processing units”), DSPs (“digital signal processing units”), ASICs (“application-specific integrated circuits”), individual analog and/or digital components. , or some other programmable logic device such as an FPGA (field programmable gate array). Data processing apparatus 10 may further include system memory and a system bus that couple various system elements, including system memory, to the processing unit. The system bus may be any of several types of bus structures, including memory buses or memory controllers, peripheral buses, and local buses, using any of a variety of bus configurations. System memory may include computer storage media in the form of volatile and/or non-volatile memory, such as read-only memory (ROM), read-write memory (RAM), and flash memory. The special purpose software may be contained in or attached to a computing device, such as magnetic media, optical media, flash memory cards, digital tape, solid state RAM, solid state ROM, etc. It may be stored in system memory or other removable/non-removable volatile/non-volatile computer storage media accessible to a computing device. The data processing device 10 has one or more communication interfaces, such as a serial interface, a parallel interface, a USB interface, a wireless interface, a network adapter, etc., as well as one or more data acquisition devices, such as an A/D converter. May contain. The special purpose software may be provided to the control unit or data processing device in any suitable computer readable medium, including recording media and read-only memory.

FIG. 5 shows a schematic diagram for measurement 1000. The figure shows two curves, one curve 400 with a leak and one curve 410 which is the background or vessel with no leak. An absorption peak 410 of increased intensity indicates that there is a leak.

Additionally, in some examples, by calculating the difference 420 between the background 410 and the peak 400, the size of the leak, such as the size of a hole or crack, can be estimated. good.

FIG. 6 shows a method 1100 for determining the health of a closed container. The closed container contains at least one type of gas. The at least one gas to be detected is either not present in the ambient atmosphere outside the container or is present in a higher concentration inside the container. The method includes the following steps.

Sending 1001 an optical signal across at least a portion of an outer surface of at least one side of the container using an optical sensor. The optical sensor is sensitive to at least one gas inside the container.

Detecting 1002 a transmitted optical signal.

Determining 1003 whether at least one gas inside the container is detected outside the container based on the detected optical signal.

The container may be a closed bag or tray containing at least one gas. Some examples may be a container with a modified atmosphere (MAP). Modified atmospheres are commonly used in packaging, for example, to improve the shelf life of food packaging, pharmaceuticals, and the like. Commonly used gases are carbon dioxide (CO ₂ ) or nitrogen (N ₂ ) to reduce the amount of oxygen (O ₂ ). This is done to slow down the growth of aerobic organisms and prevent oxidative reactions. Therefore, it is important to monitor these packages and check for leaks, eg, during packaging. Apart from _CO2 and _N2 , other gases can be monitored as well, depending on the container and product, for example, for certain products, oxygen ( _O2 ) may be good.

Method 1100 may be performed on a single container or in series, such as on a conveyor belt.

In some examples of methods, the optical sensor is a light source and a detector, and light is transmitted between the light source and the detector. The optical signal detected is an absorption signal. An example of a sensor may be, for example, Tunable diode laser absorption spectroscopy (TDLAS).

Alternatively, in some examples, the optical sensor may be based on laser induced fluorescence (LIF). The detected optical signal may be a disperse spectra or an excitation spectra. LIF sensors may use laser induced fluorescence.

To improve sensitivity, force is applied to one side of the container. Force is applied using mechanical members such as rollers or gliders. FIG. 7 shows exemplary measurements of four leaking tray packages passing through the system based on CO ₂ detection. The package has an increasing level of CO ₂ in the head space and is slightly pressured against the top film of the tray using rollers that generate a small force. As the leaking package passes through the system, the detector detects the amount of CO 2 that builds up outside the package, measured in ppm_m (parts-per-million meters of CO ₂ ), in this specific _example . Depending on the level, sharp peaks are recorded. Each measurement point represents the average CO ₂ signal within a period of 300 ms.

It should be noted that in the examples described above, it is not necessary to measure the gas concentration in absolute values. In some instances, measuring a signal related to gas concentration is sufficient. In some examples, the spectroscopic signal is related to gas pressure.

In some examples, at least one reference container is used, where the reference container has no leaks or has leaks exhibiting known characteristics. Measurements on a reference vessel provide a baseline signal that is used for comparison with signals measured on subsequent vessels.

The invention has been described above with reference to specific examples. However, examples other than those described above are equally possible within the scope of this disclosure. Different method steps other than those described above can be provided within the scope of the invention, implementing the method by hardware or software. The different features and steps of the invention may be combined in other combinations than those described. The scope of the disclosure is not limited only by the claims appended hereto.

In this specification and the claims, the indefinite articles "a" and "an" as used herein refer to "at least one" ("a" and "an"), unless it is clearly indicated to the contrary. "at least one"). The phrase "and/or" refers to "either or both" of the elements so conjoined, i.e., when present in conjunction; It should be understood that in other cases it refers to separately present elements.

Claims (14)

A method for determining the health of a sealed container containing at least one gas, the method comprising:
The method includes:
applying a mechanical force to at least a portion of the upper surface of the container;
using an optical sensor to transmit an optical signal across at least a portion of an outer surface of at least one side of the container, the optical sensor being sensitive to the at least one gas inside the container; transmitting the optical signal, the optical sensor comprising a light source that is a wavelength tunable diode laser, and a detector , the optical signal being transmitted between the light source and the detector;
detecting the transmitted optical signal;
determining whether the level of the at least one gas inside the container has changed outside the container based on the transmitted and detected optical signal , which is a Tunable Diode Laser Absorption Spectroscopy (TDLAS) signal; A method, including doing. 2. The method of claim 1, wherein the force is applied using a deformable member such as a roller or a glider. 3. A method according to claim 1 or 2, wherein the container is a MAP food package, such as a bag or a tray. A method according to any one of claims 1 to 3, comprising determining the health of the containers in series, such as on a conveyor belt. Any one of claims 1 to 4, comprising filling the periphery of the container with a neutral gas such as nitrogen (N ₂ ) during or during the transmission of the optical signal. The method described in. The method according to any one of claims 1 to 5, wherein the gas measured is carbon dioxide (CO ₂ ). 7. A method according to any preceding claim, comprising introducing gas to create a flow around the container in order to transfer leaking gas to the optical signal. A system for determining the health of a sealed container containing at least one gas, the system comprising:
a member for applying mechanical force to at least a portion of the upper surface of the container;
an optical sensor sensitive to the at least one gas, the optical sensor configured to transmit an optical signal across at least a portion of an outer surface of at least one side of the container; a light source that is a tunable diode laser, and a detector, the light signal being transmitted between the light source and the detector;
determining whether the level of the at least one gas inside the container has changed outside the container based on the transmitted and detected optical signal , which is a Tunable Diode Laser Absorption Spectroscopy (TDLAS) signal; A system comprising a control unit for 9. The system of claim 8, wherein the member is a deformable member such as a roller or a glider. 12. An extractor or suction member, such as a hole connected to a pump or fan, is placed proximate to the light sensor to increase the concentration of the at least one gas adjacent to the light sensor. 9. The system according to 8 or 9. System according to any one of claims 8 to 10, wherein a roof is arranged above the light sensor to increase the concentration of the at least one gas adjacent to the light sensor. one or more sensors are located on different sides of the container, or the light passes multiple times across at least a portion of the outer surface of at least one side of the container; Any of claims 8 to 11, wherein the light is bent using an optical system such as a mirror, or the light is bent using an optical system such as a mirror so that the light passes over two or more surfaces of the container. or the system described in item 1. System according to any one of claims 8 to 12, wherein the gas to be measured is carbon dioxide (CO ₂ ). 14. The device according to any one of claims 8 to 13, wherein the device is configured to introduce gas so as to generate a flow around the container in order to transfer leaking gas to the optical signal. system.

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